Note
Go to the end to download the full example code.
Ship drift
from datetime import datetime
from opendrift.models.shipdrift import ShipDrift
o = ShipDrift(loglevel=20)
o.add_readers_from_list([
'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml',
'https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc',
'https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml'
])
14:09:48 INFO opendrift:568: OpenDriftSimulation initialised (version 1.14.9 / v1.14.9-43-g22dbf7d)
Seed ship elements at defined position and time Note: beam/length ratio is larger than allowed, but is then clipped internally
o.seed_elements(lon=5.0, lat=63.0, radius=1000, number=1000,
time=datetime.now(),
length=80.0, beam=20.0, height=9.0, draft=4.0)
14:09:48 WARNING opendrift.models.shipdrift:180: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
14:09:48 INFO opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
14:09:52 INFO opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
14:09:52 INFO opendrift.models.basemodel.environment:230: horizontal_diffusivity: 100.000000
14:09:52 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_x_velocity: 0.000000
14:09:52 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_y_velocity: 0.000000
14:09:52 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_significant_height: 0.000000
14:09:52 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
14:09:52 INFO opendrift:1905: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
14:09:52 INFO opendrift:1905: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
14:09:52 INFO opendrift:947: Using existing reader for land_binary_mask to move elements to ocean
14:09:52 INFO opendrift:978: All points are in ocean
14:09:52 INFO opendrift:2202: 2026-04-21 14:09:48.914029 - step 1 of 24 - 1000 active elements (0 deactivated)
14:09:52 INFO opendrift.readers:64: Opening file with xr.open_dataset
14:09:56 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
14:09:56 INFO opendrift.readers:64: Opening file with xr.open_dataset
14:09:57 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
14:09:57 INFO opendrift.readers:64: Opening file with xr.open_dataset
14:09:58 INFO opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
14:10:00 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:00 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:02 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:02 INFO opendrift:2202: 2026-04-21 15:09:48.914029 - step 2 of 24 - 1000 active elements (0 deactivated)
14:10:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:04 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:04 INFO opendrift:2202: 2026-04-21 16:09:48.914029 - step 3 of 24 - 1000 active elements (0 deactivated)
14:10:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:07 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:07 INFO opendrift:2202: 2026-04-21 17:09:48.914029 - step 4 of 24 - 1000 active elements (0 deactivated)
14:10:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:09 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:10 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:10 INFO opendrift:2202: 2026-04-21 18:09:48.914029 - step 5 of 24 - 1000 active elements (0 deactivated)
14:10:11 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:11 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:12 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:12 INFO opendrift:2202: 2026-04-21 19:09:48.914029 - step 6 of 24 - 1000 active elements (0 deactivated)
14:10:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:14 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:14 INFO opendrift:2202: 2026-04-21 20:09:48.914029 - step 7 of 24 - 1000 active elements (0 deactivated)
14:10:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:16 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:16 INFO opendrift:2202: 2026-04-21 21:09:48.914029 - step 8 of 24 - 1000 active elements (0 deactivated)
14:10:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:19 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:19 INFO opendrift:2202: 2026-04-21 22:09:48.914029 - step 9 of 24 - 1000 active elements (0 deactivated)
14:10:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:21 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:21 INFO opendrift:2202: 2026-04-21 23:09:48.914029 - step 10 of 24 - 1000 active elements (0 deactivated)
14:10:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:24 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:24 INFO opendrift:2202: 2026-04-22 00:09:48.914029 - step 11 of 24 - 1000 active elements (0 deactivated)
14:10:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:27 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:27 INFO opendrift:2202: 2026-04-22 01:09:48.914029 - step 12 of 24 - 1000 active elements (0 deactivated)
14:10:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:29 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:29 INFO opendrift:2202: 2026-04-22 02:09:48.914029 - step 13 of 24 - 1000 active elements (0 deactivated)
14:10:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:33 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:33 INFO opendrift:2202: 2026-04-22 03:09:48.914029 - step 14 of 24 - 1000 active elements (0 deactivated)
14:10:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:35 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:35 INFO opendrift:2202: 2026-04-22 04:09:48.914029 - step 15 of 24 - 1000 active elements (0 deactivated)
14:10:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:38 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:38 INFO opendrift:2202: 2026-04-22 05:09:48.914029 - step 16 of 24 - 1000 active elements (0 deactivated)
14:10:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:40 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:41 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:41 INFO opendrift:2202: 2026-04-22 06:09:48.914029 - step 17 of 24 - 1000 active elements (0 deactivated)
14:10:43 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:43 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:43 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:43 INFO opendrift:2202: 2026-04-22 07:09:48.914029 - step 18 of 24 - 1000 active elements (0 deactivated)
14:10:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:46 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:46 INFO opendrift:2202: 2026-04-22 08:09:48.914029 - step 19 of 24 - 1000 active elements (0 deactivated)
14:10:47 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:47 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:48 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:48 INFO opendrift:2202: 2026-04-22 09:09:48.914029 - step 20 of 24 - 1000 active elements (0 deactivated)
14:10:50 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:50 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:50 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:50 INFO opendrift:2202: 2026-04-22 10:09:48.914029 - step 21 of 24 - 1000 active elements (0 deactivated)
14:10:52 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:52 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:52 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:52 INFO opendrift:2202: 2026-04-22 11:09:48.914029 - step 22 of 24 - 1000 active elements (0 deactivated)
14:10:54 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:54 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:55 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:55 INFO opendrift:2202: 2026-04-22 12:09:48.914029 - step 23 of 24 - 1000 active elements (0 deactivated)
14:10:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:56 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:57 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
14:10:57 INFO opendrift:2202: 2026-04-22 13:09:48.914029 - step 24 of 24 - 1000 active elements (0 deactivated)
14:10:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:10:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:11:00 INFO opendrift.models.shipdrift:310: Using Stokes drift direction as wave direction
Print and plot results
print(o)
o.plot(linecolor='orientation')
#o.animation(color='orientation', markersize=20, filename="orientation.gif", legend=['left','right'],colorbar=False,cmap='bwr')
o.animation(color='orientation', legend=['left','right'], markersize=20, colorbar=False, cmap='bwr')
===========================
--------------------
Reader performance:
--------------------
global_landmask
0:00:00.0 total
0:00:00.0 preparing
0:00:00.0 reading
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
0:00:15.3 total
0:00:00.0 preparing
0:00:15.2 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
0:00:31.9 total
0:00:00.0 preparing
0:00:31.9 reading
0:00:00.2 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
0:00:13.1 total
0:00:00.0 preparing
0:00:13.0 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
1:11.2 total time
3.9 configuration
0.0 preparing main loop
0.0 moving elements to ocean
1:07.3 main loop
0.4 updating elements
0.0 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.9)
1000 active ShipObject particles (0 deactivated, 0 scheduled)
-------------------
Environment variables:
-----
land_binary_mask
1) global_landmask
-----
x_sea_water_velocity
y_sea_water_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
2) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
x_wind
y_wind
1) https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
-----
sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
sea_surface_wave_significant_height
sea_surface_wave_stokes_drift_x_velocity
sea_surface_wave_stokes_drift_y_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
Readers not added for the following variables:
horizontal_diffusivity
Discarded readers:
Time:
Start: 2026-04-21 14:09:48.914029 UTC
Present: 2026-04-22 14:09:48.914029 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
14:11:14 INFO opendrift:4768: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
14:11:30 INFO opendrift:3191: Time to make animation: 0:00:16.161178
Total running time of the script: (1 minutes 48.718 seconds)